Pin Python point release used in CI (home-assistant#157819)

Author: emontnemery

.github/workflows/ci.yaml

@@ -41,8 +41,8 @@ env:
   UV_CACHE_VERSION: 1
   MYPY_CACHE_VERSION: 1
   HA_SHORT_VERSION: "2025.12"
-  DEFAULT_PYTHON: "3.13"
-  ALL_PYTHON_VERSIONS: "['3.13', '3.14']"
+  DEFAULT_PYTHON: "3.13.9"
+  ALL_PYTHON_VERSIONS: "['3.13.9', '3.14.0']"
   # 10.3 is the oldest supported version
   # - 10.3.32 is the version currently shipped with Synology (as of 17 Feb 2022)
   # 10.6 is the current long-term-support